Hannibal goodwin



lJNiTED STATES PATENT OFEIcE.

HANNIBAL GOODWIN, or NEWARK, NEW JEEsEY.

PH OTOTYPOGRAPHY.

SPECIFICATION forming part of Letters Patent No. 248,035, dated October11, 1881.

Application filed January 31, 1881.

To all whom it may concern:

Be it known that I, HANNIBAL GooDwIN, of the city of Newark, in thecounty of Essex and State ofNew Jersey, have invented an Improvement inPhototypography, of which the following is a specification.

By the processes now in use of preparing by photographic means ametallic or stone surface to be etched with an acid or its equivalentfor letter-press or intaglio printing, or of so preparing it forlithographic printing, it is that part of the properly-sensitized filmof organic matter covering the surface which at the outset is hardenedby the light when exposed to its action through the medium ofa negativeor positive, as the case may be, that is finally retained and made toconstitute the protecting covering in etching for letter-press orintaglio printing, or that constitutes the surface that is to take andhold the ink in lithographic printmg.

My method is the reverse of this-that is to say, by my method theabove-named hardened part of the said film is finally removed, and thesurface of the plate or stone at first covered by it is by such removallaid bare for the action of the etching agent, while the surface that isat the outset overlaid by that part of the film that is unaffected bythe light is finally protected from the action of the etching agent, oris prepared to take and hold the ink in lithographic printing.

I will proceed to describe the process by which I accomplish thisresult, and, first, the method of producing a metal or lithographicstone surface, etched in relief for letter-press printing:

I first flow the surface to be etched with a solution ofalbumen, gum,gelatine, or anyequivalent, sensitized by a suitable salt, and dry it. Ithen expose this surface to light under a positive, not a negative. Thepositive may be either a photographic positive, in line or dot, or anordinary printed engraving on paper, or a penand-ink sketch on paper, oran open meshed textile fabric, (lace, for example.) It the positive is aprinted or sketched figure on paper, the paper should be white,andpervious or made pervious tolight, so as to permit the tran smission ofsufficient light to produce the requisite photographic impression, andshould be laid with the printed or sketched surfacein con- (No model.)

tact with the plate or stone. After the photographic impression isproduced I apply a film of ink to the plate, which, besides the otheroffice it performs, acts as a help to the eye in the development of theimage, and then in the usual manner develop itthat is, remove the inkand albumen from only those parts of the plate which during the exposurewere covered by the black lines of the positive, and are therefore leftunaffected by the light. I then proceed to reverse this condition ofthings-that is,to coverwith an acid-resisting film th ose parts of thesurface that are now bare, and to remove the ink and underlying film ofalbumen from theother parts. To accomplish this result I proceed asfollows: I first preferably dust powdered rosin or other fusible resinupon the plate, which will adhere only to the parts covered by the'film.I brush off the surplus that does not adhere',thus removing it from thebare parts. I then heat till the resin just fuses. The resin is thusapplied to thoroughly protect the albumen or gum underlying the ink onthe covered parts from being penetrated by the chemical next to heapplied. It is possible, by careful manipulation, using a very dilutesolution of the acid next to be applied, and employing sufficient time,to dispense with the use of the resin; but i much prefer to employ it asdescribed, as the protection it affords to the ligh t-hardened filmrenders the following steps in the process less delicate and morecertain. I now dip the plate for about a minute in a dilute solution ofperchloride of iron or its equivalent in order to dissolve away alltrace of albumen or gum that may be still lodged in or on the surface ofthose parts of the plate that are bare, and to prepare them to receiveand hold the resinous or greasy matter now to be applied. Now, afterproperly drying the plate overheat, I preferably brush or dab on a thinfilm of a solutionof asphalt (or its equivalent, such as wax, resin, orgrease, sin gly or in combination)- in turpentine or its equivalent,covering at least all the bare parts of the plate; and then with wads ofcotton moistened with aproper solvent-such as turpentine-I remove quiteclosely the said turpentine solution, together with the ink remaining onthe plate, leaving the albumen or gelanext flow the plate with the aboveturpentine solution of asphalt or resinous or greasy matter anddistribute it thoroughly, which is best, accomplished by a vigorouswhirling in the turn-wheel, after which I keep the plate warm for ashortspace of time, especially if it be of zinc or other metal of afat-holding capacity, in order that aportion of the turpentine may carryall that is possible of the asphalt, greasy, or resinous substance downinto the plate, while the exce s evaporates. This penetration of suchagents into the plate has a considerable influence in lessening thetendency toward undercutting during the etching operation. Besides,there is now on the surface of the plate a thin sheet of the bestacid-resisting substances. This application of asphalt or itsequivalent, while it is very important, .is not indispensable.

When the surface is finally prepared for etchin g or for surface-prin tin g the parts that are to be protected from the acid in etching or areto take the ink in surface-printing are, when the asphalt or equivalentis applied, covered not merely with a lihn of fatty ink, but the inkwill be nnderlaid with a film of a substance which will contributegreatly to protecting the underlyingsurfaceof theplateorstone,preventing the acid from undercutting or making ragged lines. I next roll up theplate with ink, and then immerse it into a solution of very dilutehydrochloric acid or other solvent of light- -hardened albumen orequivalent. This acid will attack and loosen from the metal the albumen,notwithstanding the covering of ink overlying it, as will be indicated,after a few minutes, by minute gas-bubbles, which will be found to-coverthe albumen ink-covered surfaces, While the resinous asphalt or greasymatter lying next the other portions of the plate, ifsuch has beenapplied, and the overlying ink, or the ink alone it only ink has beenapplied, will remain unafl'ected. I then with a tuft of cotton sweepgently over the surface of-the plate, when only the albumen and itsoverlying ink and resinous film will comeaway, leaving bare the portionsof the plateunderneath them, while the other parts will remain coveredwith t-be'ink when ink alone has been applied, or will be penetrated byand covered with asphalt -or its equivalentwax or grease-and with acoating upon the asphalt of fatty ink, both together giving the mostfavorable protection to the parts covered against the action of theetching-acid. The surface thus prepared, whether metal or stone, isready for su rl'ace-printi n g, as 'upon lithographic stone in ordinarylithographic printing, or to be etched with a suitable acid, in relief,in the ordinary way for letter-press printing.

Second, to produce a plate etchedin intagiio for copper-plate printing,I proceed in all respects as above described, except that I employ anegative in place of a positive to get my photographic impression on mysensitized gelatine or albumen coated plate.

It will be obvious to all skilled in the art that, starting with aplatethus afi'ected through a negative and pursuing the process asdescribed, a surface etched in intaglio will be the result.

The advantages of this method over any heretofore practiced are verygreat. .One of the most important is the opportunity it affords for theemployment of a positive instead of a negative as the medium forproducing the photographic impression on the sensitized plate or stoneto be etched in relief for letterpress printing.

it. There are, as is well known, inevitable difficulties in securing aphotographic negative in very line lines, because of the clouding andchoking up of said lines in the operation of development and ofintensification, which diliicnlties do not accompany a photographicpositive, and hence results unobtainable by the former are secured bythe latter.

I). As is well known, better definition in a picture npon metal or stonecan be secured by contact photographic printing than when the picture istransferred.

0. A finer image can be gotten upon the plate through a positive than anegative. fact this image is somewhat finer than the positive itselfwhich is used, while a negative produces an image that is somewhatcoarser than itself, the lines coming out broader than in the negative.

d. A majority of the subjects required to be produced are themselvespositive, such as printed or penned sketches on paper, or open textilefabrics, and by my invention I can use them direct -without'theintervention of the.

camera.

0. The use of a positive will, while a negative will not, permit theapplication of resinous or greasy matter to the lines to be etched inrelief previous to the application of fatty ink, whereby the said linesare protected from the etching-acid to a degree unobtainable by thesimple application of ink or of albumen and fatty ink, so that the linesare etched with less raggedness and undercutting and less indentation ofsurface than by the ordinary process.

f. My process is more direct and simple and requires less time than thetransfer process heretofore employed, and while not perhaps much morespeedy than the ordinary direct method, it possesses many advantagesover that method, as will be readily understood and appreciated by thoseskilled in the art.

g. Many of the difficulties and objectionable results that are-incidentto the common transfer processes are obviated by mine, such as thefrequent failure of the image on the transferpaper to develop theliability of carrying away very fine lines in the operation ofdeveloping the image on the transfer-paper the blockingup of smallspaces in making the transfer; the liability to spoil the work by theslipping of the transfer-paper upon the plate in laying it in; theinjury often caused by the puckerin g of the transfer when the pressureof the press is applied; the failure that sometimes occurs to pro duce acomplete transfer by reason of the nonpenetration of the ink into theplate after the pressure is applied, thus leaving the image or part ofit on the paper; the mischief often done from the filling up ofthesmallest spaces by the application of fresh ink after the transfer ismade upon the metal.

h. As is well known, raggedness of line in ordinary processes of etchingin relief arises largely from the reinking, rosining, and melting, whichare necessary immediately after the first shallow etching, whereas bythe penetration of the surface by an oily asphalt the first etching maybe carried so deep that the after application of ink and rosin cannotproduce such raggedness.

The preliminary steps of the process I have above described up to thepoint at which the photographic impression is produced upon the film ofsensitized gelatine or albumen through the medium ofeither a negative orpositive, the removal from the surface of the metal or stone of theparts of the film not hardened by the light, and the covering with inkof the hardened parts of the film that remain, are not new; butheretofore when this stage has been reached the practice has been,whether by the direct or transfer process, to immediately commence theetching operation by the application of the acid, either for a relief orfor an intaglio, or the surface without further modification 'is'uscdfor surface-printing; but by my new process, having reached the stage orcondition last above referred to, 1 proceed to reverse the conditions ofthe surface-thatis to say, to reverse the film image now on thesurface--and to cover the now bare parts with a film thatshallconstitute the image to be reproduced. By this reversal of theconditions of the surface it re suits that, if a positive is used as themedium for getting the photographicimpression on the sensitized gelatineor albumen covered plate or stone, the same positive or image isproduced for the printing-surface, and if a negative is used as suchmedium the same negative is produced for the printingsurface.

The process described in the last preceding paragraph I believe to benew, as is also the process described of covering the protected parts ofthe plate or stone under the ink with a film of asphalt or itsequivalent, such as rosin, wax, grease, &c., singly or in combina-IlOI].

What I claim as my invention, and desire to secure by Letters Patent, is

1. In the process of relief etching on a metal or stone surface with anacid for the produc tion of printing-surfaces, the employment of apositive as the medium of getting a photographic impression in thesensitized film of al- :or stone surface with acid for the production ofintaglio-printing surfaces, the employment of a negative as the mediumof getting a photographic impression in the sensitized film of albumen,and using said photographic impression in the operation of covering witha film offatt-y ink or its equivalent the parts only of said metal orstone surface that are not to be cut by the acid in the etchingprocess,substantially as described.

3. In the process of etching with acid metal or stone surfaces fortheproduction of printingsnrfaces, the method herein described ofcovering with a protecting-film of a substance that will resist theetching agent only those parts of the said surface that are not to becut thereby, consisting, first, in covering said surface entirely with afilm of albumen or its equivalent properly sensitized, so that theaction of the light is to harden and render insolublein water-thealbumen; then submitting said prepared surface to the action of lightunder either a. negativeor-positive, and washing away the parts of thefilm not affected by the light in the usual way; then applying to thissurface a dilute solution of perchloride of iron or its equivalentsuchas a mixture of verdigris and sal-ammoniac-to dissolve away theremainingforeign matter from the bare parts of the surface and prepareit to receive and hold the substance next to be applied; then coveringthe surface with a film of asphalt, grease, or its equivalent, depositedfrom a solution; and, lastly, removing by the use of a suitable solventthe remaining filin of albumen that has been hardened by the light andits overlying asphalt, leaving the parts of the surface not intended tobe cut by the etching agent, or that are intended to take and hold theink,covered by the film of asphalt or equivalent, substantially asdescribed.

Witness my hand this 27th day of January, 1881.

HANNIBAL GOODWIN.

Witnesses: f

A. G. W. VERMILYA, HENRY EroHLrNG.

